Really, if they lied to Congress, the main response to that should be looking for impeachment and removal from office, not prosecution.
That's the tool that Congress has to deal with misbehaving officials.
Don't look to the executive branch to police executive branch officials. That's a conflict of interest. And that is exactly why the legislative branch has the power of impeachment.
Say it loud, if you think these people lied to Congress then we need to hold our congresspeople accountable for responding with the impeachment tool that they have.
And if they don't, hold them accountable for not, and stop re-electing these people.